Before you hire a Blaster for any project make sure they have at least five (5) years experience with their own company.
That they do everything from repairs, blasting and painting.
That they carry full Contractors Insurance for at least $2 Million and have full WCB for all workers.
You can also check with NASB and get a report on known contractors in the business.http://www.nasb.ca
Make sure that the painter is able to use an Airless Paint Sprayer, and if not then they don't have the experience need to stain your home.